- Structure-Odor Activity Studies on Derivatives of Aromatic and Oxygenated Monoterpenoids Synthesized by Modifying p-Cymene
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Thymoquinone was recently reported as having a unique pencil-like odor and being the impact compound for the cedar-like and cedar wood-based product smell such as pencils. The compounds thymol and carvacrol are structurally related odorants commonly found in plants and foods such as thyme and oregano, also having a significant contribution to their overall aroma. However, a systematic elucidation of the sensory properties in this class of oxygenated, aromatic monoterpenoids has not been carried out. To close this gap and gain new insights into structure-odor relationships leading to pencil-like and woody odors, 19 structurally related derivatives of p-cymene starting from thymol and carvacrol were synthesized and characterized. The compounds had odor thresholds ranging from 2.0 ng/L air to 388.8 ng/L air, being lowest for thymol and carvacrol and highest for thymohydroquinone. The compounds smelled mostly thyme-like, oregano-like, and pencil-like with phenolic, earthy, and medicinal variations in their odor character, which could be successfully linked to structural motifs.
- Schreiner, Linda,Bauer, Johannes,Ortner, Eva,Buettner, Andrea
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supporting information
p. 834 - 842
(2020/03/30)
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- Synthesis and evaluation of antioxidant and antimicrobial properties of thymol containing pyridone moieties
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Various derivatives of 1,2-dihydro-6-(4-hydroxy- 5-isopropyl-2- methylphenyl)-2-oxo-4-arylpyridine-3-carbonitrile (IVa-m) were synthesized and characterized. Their antioxidant and antimicrobial properties were evaluated by measuring their activity in vitro. Among the newly synthesized derivatives IVg, IVh, IVi, IVj, IVk, IVl, and IVm showed good antioxidant activity. However, all derivatives show better antibacterial and antifungal properties than that of parent thymol. The probable mechanism, particularly for antioxidant properties of these compounds is proposed. Springer Science+Business Media, LLC 2011.
- Nagle,Pawar,Sonawane,Bhosale,More
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experimental part
p. 1395 - 1402
(2012/07/31)
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- Regioselective fries rearrangement and friedel-crafts acylation as efficient routes to novel enantiomerically enriched ortho-acylhydroxy[2.2]paracyclophanes
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Two useful approaches to ortho-acylhydroxy[2.2]paracyclophanes, starting from 4-hydroxy[2.2]paracyclophane, have been developed. TiCl4-catalyzed Fries rearrangement and direct acylation occur regioselectively (to the ortho position with respect to the hydroxy group), leading to 4-acetyl-5-hydroxy[2.2]paracyclophane (3) and 4-benzoyl-5-hydroxy[2.2]-paracyclophane (4) in high to excellent chemical yields. For compound 4, an X-ray investigation has been performed. ortho-Acylhydroxy[2.2]paracyclophanes 3 and 4 have been obtained in enantiomerically enriched forms (ee 92-99%) and the absolute configurations of their enantiomers have been determined.
- Rozenberg, Valeria,Danilova, Tat'yana,Sergeeva, Elena,Vorontsov, Evgenii,Starikova, Zoya,Lysenko, Konstantin,Belokon', Yuri
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p. 3295 - 3303
(2007/10/03)
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- The Photo-Fries Rearrangement of 2,5-Disubstituted Phenyl Acetates
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In a homogenous solution, the photo-Fries rearrangement of 2,5-disubstituted phenyl acetates gives ortho-hydroxyacetophenones as major photoproducts.The ortho/para ratio can be increased by using a highly viscous medium or restricted spaces such as those in zeolites.On the other hand, micellar solutions have little effect.
- Suau, Rafael,Torres, Gregorio,Valpuesta, Maria
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p. 1311 - 1314
(2007/10/02)
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